The Crown Mark is applied to any item that is made from a solid gold alloy, not gold plated...gold plating, rolled gold etc. means nothing in precious metal terms and virtually is worthless. In the UK there are five qualities of gold able to be hallmarked, 24 carat (999 parts gold) 22 carat (916 parts gold), 18 carat (750 parts gold), 14 carat (585 parts gold) and 9 carat (375 parts gold). But what does carat mean? Pure gold is has no impurities and is classified as having 1000 parts pure gold. In contrast 18 carat has 750 parts pure gold with 250 parts alloy. It is marked in the hallmark. When assayed, if the assay comes back as, say, 749 rather than 750, the assay fails and the article will not be able to be marked as 18ct...In such cases the next lower carat is marked. ie 14 carat. If 9 carat fails the assay it is destroyed.
This photograph shows gold being melted and alloyed in our studio to make 18ct yellow gold used to make the leaves and wire in one of the tiaras. When we melt and alloy any metal we always add a little extra 24 carat fine gold to the mix to give a high assay of 755 or more so we can be assured of it's purity count when being hallmarked.
The Sterling Silver Lion. As with the gold standard, pure silver is classed as having 1000 parts pure silver. Sterling silver, has a minimum of 925 pure silver and 75 parts alloy, usually copper. It is marked 925 in a shield like so...
The final mark is the Date Mark. Formed of a single letter in a shield. The shield, along with the letter, is changed every year. This can, as does, make analysing hallmarks difficult as they are monstly small, look very similar under magnification in sheild-shape and font style. A slight error in analysing them and you could be many years out.
We are proud to say that we've had all our pieces assayed and marked, by hand, at this prestigious and historic establishment, The London Assay Office.
Our finished hallmark on one of the tiaras. Hand struck at the London Assay Office. Being hand struck means slight discrepancies in the alignment of the marks showing that humans aren't as perfect as machines, a good thing when it comes to art.
As with the mis-aligned marks when hallmarking, the pressure caused when striking the metal punches causes planishing marks on the rear side. Rather than re-work the metal we left them visible as another sign of our tiaras being handmade..
The above is just a snippet of hallmarking and its many facets. More information can be seen here on The Goldsmiths Company website. The Goldsmiths Company.